Conviction

“Conviction” is the sort of nightmare scenario that can only be conjured up by reality: A man is wrongly convicted for a crime he did not commit. His sister, convinced of his innocence and unable to pay for better legal representation, resolves to transform herself into a lawyer in a Hail Mary effort to free her brother.

If this had originated from the mind of Hollywood, the siblings would be replaced by lovers, and the wannabe attorney would be a crack shot with a Glock.

Fortunately, “Conviction” director Tony Goldwyn (TV’s “Dexter”) doesn’t muck up the real-life story of Betty Anne Waters. A high school dropout, the Massachusetts native and mother of two put herself through law school and passed the bar solely to help win the release of her brother, Kenny, unjustly sentenced to life in prison for murder.

Betty Anne’s journey took 18 years, and not without some personal cost. Her marriage fell apart, and her two sons opted to live with their father. But in 2001, DNA evidence finally led to Kenny’s exoneration.

Don’t worry that I’m spoiling the movie: It’s all a matter of public record. “Conviction” is engrossing not because you’re unsure of the outcome, but because you actually care about the lives of those being affected. Such is the result of solidly crafted filmmaking and a pitch-perfect cast that does justice to a mind-boggling tale of injustice.

As played by Hilary Swank (“Amelia”), Betty Anne is a working-class bartender whose life is given a single-minded purpose when Kenny (Sam Rockwell, “Iron Man 2″) is targeted for the 1980 stabbing death of a woman in her trailer home. As the town ne’er-do-well, Kenny is a convenient suspect for the gung-ho investigating police officer (Melissa Leo, “Everybody’s Fine”). When two of his ex-girlfriends say he confessed the crime to them, it doesn’t take long for a jury to hand down a sentence of life in prison without parole.

Betty Anne assumes the burden of fighting the conviction. She earns a GED, then a college degree, before tackling the rigors of law school. Eventually, Betty Anne reaches out to the Innocence Project, a New York-based organization that aids in wrongful conviction cases, and its high-profile founder, Barry Scheck (Peter Gallagher, TV’s “Covert Affairs”).

“Conviction” isn’t quite as fearless as its heroine. Although it incorporates an intriguing nonlinear narrative, the movie embraces its fair share of clich